Transcriptome Analysis Of Tuber Enlargement Of Bikeqi Yam (Dioscorea Opposita Thunb.) In Inner Mongolia

The yam(Dioscorea opposita Thunb.)is one of the ten important edible root(block)stem crops in the world at present.Yam tuber is rich in various nutrients and has good market prospect and industrial development potential.In this study,Bikeqi yam was used as the test material.We used a combination of RNA-seq and Iso-seq transcriptomics sequencing technology to sequence tubers at different developmental stages during the tuber expansion period of yam,and screened differentially expressed genes associated with the tuber expansion period by bioinformatics analysis.Our research provides theoretical basis for analyzing tuber enlargement,improving tuber quality and improving yam yield.The main conclusions are as follows:(1)Transcriptomic analysis showed that raw reads ranged from 43112719 to56714129,and Clean reads after quality control ranged from 41180813 to 53748422,with an average length of 60220 bp and N50 of 123317 b.The average proportion of Clean reads in Raw Reads was 95.72%.Clean reads and reference sequences of Bikeqi were compared and analyzed,and the results ranged from 76.49% to 89.44%.(2)By comparing the data of 12 large and long yam transcriptome libraries(a total of 6 comparison groups),the screening results of differentially expressed genes in each group were as follows: 206(D＿120 VS D＿90),2450(D＿150 VS D＿90),2746(D＿180 VS D＿90),446(D＿150 VS D＿120),2376(D＿180 VS D＿120),1396(D＿180 VS D＿150).(3)Through GO functional annotation of differentially expressed genes(DEGs)in the 6 comparison groups,the number of entries annotated as enriched in each comparison group was as follows: 572(D＿120 VS D＿90),2013(D＿150 VS D＿90),1959(D＿180 VS D＿90),446(D＿150 VS D＿120),1872(D＿180 VS D＿120),1536(D＿180 VS D＿150).In general,the order of the number of genes annotated to different components is as follows: biological processes,Molecular function and Cell component.(4)KEGG metabolic pathway enrichment analysis was performed on differentially expressed genes(DEGs)of the 6 comparison groups,and the number of enriched pathways in each group was as follows: 36(D＿120 VS D＿90),101(D＿150 VS D＿90),102(D＿180 VS D＿90),56(D＿150 VS D＿120),108(D＿180 VS D＿120),99(D＿180 VS D＿150).The analysis revealed that ɑ-linolenic acid metabolism and linoleic acid metabolism were significantly enriched in all comparative combinations,with the beet pigment biosynthesis pathway being significantly enriched only in the D＿150 vs D＿90 comparative combination.(5)The metabolic pathways of linoleic acid metabolism,alpha linolenic acid metabolism and beet pigment biosynthesis of Bikeqi yam were analyzed.The results showed that 43 genes and 3 enzymes were involved in the regulation of linoleic acid metabolism.65 genes,corresponding to 13 enzymes involved in regulation of Alpha linolenic acid metabolism;Six genes,corresponding to 1 enzyme,were involved in the regulation of beet pigment biosynthesis.